sticker: new library for storing dynamic information about songs

"Stickers" are pieces of information attached to existing MPD objects
(e.g. song files, directories, albums).  Clients can create arbitrary
name/value pairs.  MPD itself does not assume any special meaning in
them.

1 files changed, 361 insertions, 0 deletions

diff --git a/src/sticker.c b/src/sticker.c
new file mode 100644
index 000000000..e596fd97c
--- /dev/null
+++ b/src/sticker.c
@@ -0,0 +1,361 @@
+/*
+ * Copyright (C) 2003-2009 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include "sticker.h"
+
+#include <glib.h>
+#include <sqlite3.h>
+#include <assert.h>
+
+#undef G_LOG_DOMAIN
+#define G_LOG_DOMAIN "sticker"
+
+static const char sticker_sql_create[] =
+	"CREATE TABLE IF NOT EXISTS sticker("
+	"  type VARCHAR NOT NULL, "
+	"  uri VARCHAR NOT NULL, "
+	"  name VARCHAR NOT NULL, "
+	"  value VARCHAR NOT NULL"
+	");"
+	"CREATE UNIQUE INDEX IF NOT EXISTS"
+	" sticker_value ON sticker(type, uri, name);"
+	"";
+
+static const char sticker_sql_get[] =
+	"SELECT value FROM sticker WHERE type=? AND uri=? AND name=?";
+
+static const char sticker_sql_update[] =
+	"UPDATE sticker SET value=? WHERE type=? AND uri=? AND name=?";
+
+static const char sticker_sql_insert[] =
+	"INSERT INTO sticker(type,uri,name,value) VALUES(?, ?, ?, ?)";
+
+static const char sticker_sql_delete[] =
+	"DELETE FROM sticker WHERE type=? AND uri=?";
+
+static sqlite3 *sticker_db;
+static sqlite3_stmt *sticker_stmt_get, *sticker_stmt_update,
+	*sticker_stmt_insert, *sticker_stmt_delete;
+
+static sqlite3_stmt *
+sticker_prepare(const char *sql)
+{
+	int ret;
+	sqlite3_stmt *stmt;
+
+	ret = sqlite3_prepare_v2(sticker_db, sql, -1, &stmt, NULL);
+	if (ret != SQLITE_OK)
+		g_error("sqlite3_prepare_v2() failed: %s",
+			sqlite3_errmsg(sticker_db));
+
+	return stmt;
+}
+
+void
+sticker_global_init(const char *path)
+{
+	int ret;
+
+	if (path == NULL)
+		/* not configured */
+		return;
+
+	/* open/create the sqlite database */
+
+	ret = sqlite3_open(path, &sticker_db);
+	if (ret != SQLITE_OK)
+		g_error("Failed to open sqlite database '%s': %s",
+			path, sqlite3_errmsg(sticker_db));
+
+	/* create the table and index */
+
+	ret = sqlite3_exec(sticker_db, sticker_sql_create, NULL, NULL, NULL);
+	if (ret != SQLITE_OK)
+		g_error("Failed to create sticker table: %s",
+			sqlite3_errmsg(sticker_db));
+
+	/* prepare the statements we're going to use */
+
+	sticker_stmt_get = sticker_prepare(sticker_sql_get);
+	sticker_stmt_update = sticker_prepare(sticker_sql_update);
+	sticker_stmt_insert = sticker_prepare(sticker_sql_insert);
+	sticker_stmt_delete = sticker_prepare(sticker_sql_delete);
+
+	if (sticker_stmt_get == NULL || sticker_stmt_update == NULL ||
+	    sticker_stmt_insert == NULL || sticker_stmt_delete == NULL)
+		g_error("Failed to prepare sqlite statements");
+}
+
+void
+sticker_global_finish(void)
+{
+	if (sticker_db == NULL)
+		/* not configured */
+		return;
+
+	sqlite3_finalize(sticker_stmt_delete);
+	sqlite3_finalize(sticker_stmt_update);
+	sqlite3_finalize(sticker_stmt_insert);
+	sqlite3_close(sticker_db);
+}
+
+bool
+sticker_enabled(void)
+{
+	return sticker_db != NULL;
+}
+
+char *
+sticker_load_value(const char *type, const char *uri, const char *name)
+{
+	int ret;
+	char *value;
+
+	assert(sticker_enabled());
+	assert(type != NULL);
+	assert(uri != NULL);
+	assert(name != NULL);
+
+	if (*name == 0)
+		return NULL;
+
+	sqlite3_reset(sticker_stmt_get);
+
+	ret = sqlite3_bind_text(sticker_stmt_get, 1, type, -1, NULL);
+	if (ret != SQLITE_OK) {
+		g_warning("sqlite3_bind_text() failed: %s",
+			  sqlite3_errmsg(sticker_db));
+		return false;
+	}
+
+	ret = sqlite3_bind_text(sticker_stmt_get, 2, uri, -1, NULL);
+	if (ret != SQLITE_OK) {
+		g_warning("sqlite3_bind_text() failed: %s",
+			  sqlite3_errmsg(sticker_db));
+		return false;
+	}
+
+	ret = sqlite3_bind_text(sticker_stmt_get, 3, name, -1, NULL);
+	if (ret != SQLITE_OK) {
+		g_warning("sqlite3_bind_text() failed: %s",
+			  sqlite3_errmsg(sticker_db));
+		return false;
+	}
+
+	do {
+		ret = sqlite3_step(sticker_stmt_get);
+	} while (ret == SQLITE_BUSY);
+
+	if (ret == SQLITE_ROW) {
+		/* record found */
+		value = g_strdup((const char*)sqlite3_column_text(sticker_stmt_get, 0));
+	} else if (ret == SQLITE_DONE) {
+		/* no record found */
+		value = NULL;
+	} else {
+		/* error */
+		g_warning("sqlite3_step() failed: %s",
+			  sqlite3_errmsg(sticker_db));
+		return false;
+	}
+
+	sqlite3_reset(sticker_stmt_get);
+	sqlite3_clear_bindings(sticker_stmt_get);
+
+	return value;
+}
+
+static bool
+sticker_update_value(const char *type, const char *uri,
+		     const char *name, const char *value)
+{
+	int ret;
+
+	assert(type != NULL);
+	assert(uri != NULL);
+	assert(name != NULL);
+	assert(*name != 0);
+	assert(value != NULL);
+
+	assert(sticker_enabled());
+
+	sqlite3_reset(sticker_stmt_update);
+
+	ret = sqlite3_bind_text(sticker_stmt_update, 1, value, -1, NULL);
+	if (ret != SQLITE_OK) {
+		g_warning("sqlite3_bind_text() failed: %s",
+			  sqlite3_errmsg(sticker_db));
+		return false;
+	}
+
+	ret = sqlite3_bind_text(sticker_stmt_update, 2, type, -1, NULL);
+	if (ret != SQLITE_OK) {
+		g_warning("sqlite3_bind_text() failed: %s",
+			  sqlite3_errmsg(sticker_db));
+		return false;
+	}
+
+	ret = sqlite3_bind_text(sticker_stmt_update, 3, uri, -1, NULL);
+	if (ret != SQLITE_OK) {
+		g_warning("sqlite3_bind_text() failed: %s",
+			  sqlite3_errmsg(sticker_db));
+		return false;
+	}
+
+	ret = sqlite3_bind_text(sticker_stmt_update, 4, name, -1, NULL);
+	if (ret != SQLITE_OK) {
+		g_warning("sqlite3_bind_text() failed: %s",
+			  sqlite3_errmsg(sticker_db));
+		return false;
+	}
+
+	do {
+		ret = sqlite3_step(sticker_stmt_update);
+	} while (ret == SQLITE_BUSY);
+
+	if (ret != SQLITE_DONE) {
+		g_warning("sqlite3_step() failed: %s",
+			  sqlite3_errmsg(sticker_db));
+		return false;
+	}
+
+	ret = sqlite3_changes(sticker_db);
+
+	sqlite3_reset(sticker_stmt_update);
+	sqlite3_clear_bindings(sticker_stmt_update);
+
+	return ret > 0;
+}
+
+static bool
+sticker_insert_value(const char *type, const char *uri,
+		     const char *name, const char *value)
+{
+	int ret;
+
+	assert(type != NULL);
+	assert(uri != NULL);
+	assert(name != NULL);
+	assert(*name != 0);
+	assert(value != NULL);
+
+	assert(sticker_enabled());
+
+	sqlite3_reset(sticker_stmt_insert);
+
+	ret = sqlite3_bind_text(sticker_stmt_insert, 1, type, -1, NULL);
+	if (ret != SQLITE_OK) {
+		g_warning("sqlite3_bind_text() failed: %s",
+			  sqlite3_errmsg(sticker_db));
+		return false;
+	}
+
+	ret = sqlite3_bind_text(sticker_stmt_insert, 2, uri, -1, NULL);
+	if (ret != SQLITE_OK) {
+		g_warning("sqlite3_bind_text() failed: %s",
+			  sqlite3_errmsg(sticker_db));
+		return false;
+	}
+
+	ret = sqlite3_bind_text(sticker_stmt_insert, 3, name, -1, NULL);
+	if (ret != SQLITE_OK) {
+		g_warning("sqlite3_bind_text() failed: %s",
+			  sqlite3_errmsg(sticker_db));
+		return false;
+	}
+
+	ret = sqlite3_bind_text(sticker_stmt_insert, 4, value, -1, NULL);
+	if (ret != SQLITE_OK) {
+		g_warning("sqlite3_bind_text() failed: %s",
+			  sqlite3_errmsg(sticker_db));
+		return false;
+	}
+
+	do {
+		ret = sqlite3_step(sticker_stmt_insert);
+	} while (ret == SQLITE_BUSY);
+
+	if (ret != SQLITE_DONE) {
+		g_warning("sqlite3_step() failed: %s",
+			  sqlite3_errmsg(sticker_db));
+		return false;
+	}
+
+	sqlite3_reset(sticker_stmt_insert);
+	sqlite3_clear_bindings(sticker_stmt_insert);
+
+	return true;
+}
+
+bool
+sticker_store_value(const char *type, const char *uri,
+		    const char *name, const char *value)
+{
+	assert(sticker_enabled());
+	assert(type != NULL);
+	assert(uri != NULL);
+	assert(name != NULL);
+	assert(value != NULL);
+
+	if (*name == 0)
+		return false;
+
+	return sticker_update_value(type, uri, name, value) ||
+		sticker_insert_value(type, uri, name, value);
+}
+
+bool
+sticker_delete(const char *type, const char *uri)
+{
+	int ret;
+
+	assert(sticker_enabled());
+	assert(type != NULL);
+	assert(uri != NULL);
+
+	sqlite3_reset(sticker_stmt_delete);
+
+	ret = sqlite3_bind_text(sticker_stmt_delete, 1, type, -1, NULL);
+	if (ret != SQLITE_OK) {
+		g_warning("sqlite3_bind_text() failed: %s",
+			  sqlite3_errmsg(sticker_db));
+		return false;
+	}
+
+	ret = sqlite3_bind_text(sticker_stmt_delete, 2, uri, -1, NULL);
+	if (ret != SQLITE_OK) {
+		g_warning("sqlite3_bind_text() failed: %s",
+			  sqlite3_errmsg(sticker_db));
+		return false;
+	}
+
+	do {
+		ret = sqlite3_step(sticker_stmt_delete);
+	} while (ret == SQLITE_BUSY);
+
+	if (ret != SQLITE_DONE) {
+		g_warning("sqlite3_step() failed: %s",
+			  sqlite3_errmsg(sticker_db));
+		return false;
+	}
+
+	sqlite3_reset(sticker_stmt_delete);
+	sqlite3_clear_bindings(sticker_stmt_delete);
+
+	return true;
+}